Name _____________________________________ Period _________
You will need a calculator to complete this homework.
Part A
1. Frequency (speed) of a wave is determine by ____________/____________. This measurement is called ________________________.
2. Calculate the missing values A and B from the following table:
Frequency
A
1.2 meters/second
Distance
3000 meters
B
Time
150 seconds
30 seconds
A ______________________ B ______________________
Part B
Ten students are standing in the Baltimore Harbor watching the start of a marathon. They measure the time difference between seeing smoke and hearing the bang of the starter gun. Their times were:
3.8 seconds
4.2 seconds
3.8 seconds
4.0 seconds
4.4 seconds
3.8 seconds
4.0 seconds
3.6 seconds
4.2 seconds
4.2 seconds
1. The average time for the group is ___________________________.
2. Calculate the distance from the students to the Baltimore Harbor starting line, if the speed of sound is 340 meters/second.
X average time in seconds
= 340 meters/second
The distance from the group to the starting gun in meters (X) = _____________________

Part C
1. A diver 4.5 kilometers (km) away from a diving boat hears the warning siren 3 seconds after it actually rang. What is the speed of sound under water? Show work below:
2. A person at the mouth of a cave shouts, and hears an echo from the back wall of the cave. Using a stopwatch, she times 1 second between shouting and hearing the echo.
Calculate how far away she is from the back wall of the cave. The speed of sound is 340 meters per second (m/s).
3. A source produces 400 waves every minute (1 minute = 60 seconds). If the speed of the waves is 8 mm/second (millimeters per second), calculate the distance between each trough.
Part D
1. Give an example showing that waves can travel through solids. _________________________
__________________________________________________________________________________________
2. Give an example showing that waves can travel through gas. _________________________
__________________________________________________________________________________________
3. In the Star Wars films, there are many loud explosions as spaceships blow up. In reality, you wouldn’t hear the explosions at all. Why not? ______________________________________________
__________________________________________________________________________________________